The present invention relates to a plug connection for the detachable fitting of a prosthesis structure or the like to a fixing head of a peg, tooth post or the like. The peg or tooth post is provided with a plug part on a fixed head having an all-around constriction in a plane substantially perpendicular to the longitudinal axis of symmetry of the fixing head, a socket part carrying the prosthesis structure and having elastic clamping ring inserted on the head with the ring engaging behind a construction of the plug part to form a positive connection between the plug part and socket part. The socket part is thus elastically mounted with respect to the plug part with regard to impact stresses occurring substantially in the direction of longitudinal axis of symmetry of the fixing head.
In a known plug connection of this type, the plug part connected to the fixing head of the peg or tooth post or the like is substantially spherically constructed. A large diameter area of the sphere is engaged behind in the vicinity of the constriction facing the fixing head by a clamping ring constructed as an O-ring made from a relative flexible plastic and/or rubber material. The clamping ring simultaneously ensures the elastic mounting of the socket part and therefore the prosthesis structure in the direction of longitudinal axis of symmetry of the fixing head. The front inner face of the socket part, which is substantially at right angles to the longitudinal axis of symmetry of the plug connection, is kept spaced from the end of the plug part remote from the fixing head so that in the case of impact stresses or the like, even in the case of a chewing movement, the forces acting in the direction of longitudinal axis of symmetry do not lead to the pressing of the socket part and therefore, the prosthesis structure against the plug part and consequently onto the fixing head of the peg or tooth post. Thus, in a desirable manner, it is ensured that all of the forces exerted on the prosthesis structure are not deflected to the peg or the tooth post and instead, following a movement in the direction of longitudinal axis of symmetry, for example, 0.5 mm, the dental prosthesis or the like is supported on the jaw ridge. However, as a result of the "floating" mounting of the socket part due to the O-ring fulfilling both the clamping and holding function, as well as the resilient bearing function, lateral movements occur and after a short time lead to the destruction of the O-ring. Thus, the known plug connection suffers from the disadvantage that it wears after a relative short time so that frequently after a few weeks the O-ring or, if as is usually the case the prosthesis is carried by several such plug connections, the O-rings have to be replaced.
Another plug confection for prosthesis structure is realized in that the fixing head of the peg or tooth post or the like is provided with a "socket" in the form of a hemispherical shell made from polyoxymethylene or the like and is provided with an undercut with which it is engaged in a snapping fit on a spherical "plug" of the prosthesis structure. However, this plug connection suffers from the disadvantage that due to the necessarily relatively rigid material of the 1/2 or 3/4 spherical shell of the material such as polyoxymethylene, the vertical elasticity is not adequate. Thus, compressive stresses of the prosthesis structure cannot be supported on the jaw ridge and are instead completely transferred to the peg or tooth post or the like with all the disadvantages consequently resulting therefrom. Another disadvantage of this plug connection is that between the spherical head and the spherical shell, deposits can occur, for example, in the form of fine-grained lime which will cause a rapid wear of the spherical head of the plug connection.